2002 Ford Ranger

Electrical problem
2002 Ford Ranger 4 cyl Two Wheel Drive Automatic 82,000 miles

Hi, I have a number 2 (10a) fuse constantly blowing. Air bag light is on and it controls blower motor relay, backup lights etc. (2002 ford ranger) I went up to 20a and no further and it still keeps going out. I checked the blower motor and even unplugged it, replaced the blower relay, and none of this helped. It blows when I sometimes step on the brake if it is already driving, but lately I can't get it out of park without the fuse blowing when I operate the gear shifter. Any help?
October 28, 2008.

Check wiring harness going to rear tail lights
looking for short to ground
do you have a trailer wiring if so recheck the wires
was any bulbs replace make sure correct bulbs were used

need manual CHECK IT @

Oct 28, 2008.